I still get amuzed by the number of electricians I meet on the job that don't realize you can't run seperate phases to the same three phase load in seperate conduits. I've had to explain the concept of building a "choke" to more guys than I can shake a stick at. It's almost as bad as the concept of splicing copper to aluminum in a split-bolt without the divider. Anyone else have anything to add about this?
One of the best melt downs I've ever seen was in a holiday in that we had as a customer. The maintanance man for the hotel was supposedly going to tighten the lugs on the main, he threw the switch to "off", opened the door, and stuck his bare metal allen wrenck into the lug. The mechanism supposedly allowed him to open the door without actually shutting down the power.( most likely he used his screwdriver to trip the latch and hadn't really shut it down.) The lugs were hot, he took a 480v hit, dropped the wrench into the gear and ended up blowing a 3'x5' hole in the F.P.&L. vault wall. We showed up and overnighted a new switch in from Alabama or someplace. striped the old out, installed new and got the 400 unit hotel back on line in 36 hours. Damn I was tired! The maintanance guy survived but,last I heard, was starting to have digestive problems and trouble walking.